One of the biggest hurdles for a radiologist is the volume of images that must be analyzed every day for diagnostic purposes. Often, these images are collected from remote locations, such as individual physicians' offices or emergency centers. Medical professionals transmit the images to a central radiology unit where trained professionals “read” the image to determine the next course of action for treatment. Radiology professionals face the task of analyzing hundreds of images per day and providing a diagnosis for every patient in a timely manner. This pressure is compounded by the fact that the person reading the image may have no personal communication with the individual patient or with the person who actually performed the imaging. In some cases, the imaging specialist or attending physician sends a note with a brief explanation of the injury being imaged. Often, however, these notes are insufficient to give the radiologist reading the image a clear focus of the exact problem to look for on the multitude of images associated with a patient or group of patients.
As a result, the radiology professional's job is of an extremely broad scope, including the review of many different types of images and particular areas on those images. With better information regarding the actual area of medical interest on an image, the radiologist could focus the review to the most pertinent areas.
There is a need in the radiological arts, therefore, for a product that marks a patient's body to point out the most pertinent area on a corresponding radiological image.
Prior efforts to meet this need have included various attempts to add pointers to medical images. For instance, some imaging professionals place a foreign object on the patient during the scan to emphasize an area of interest to the person reading the image. Unfortunately, foreign objects also bring forth the possibility of obscuring a view of the medical problem on the image. Similarly, various directional arrows are sometimes placed on the image to direct the radiologist to a particular region on the scan. Unfortunately, these can be dislodged inadvertently, pointing to the entirely wrong area.
Still, however, with medical imaging taking on such high tech features as 3-D imaging and higher resolution scanning at various angles, efforts to incorporate directional arrows on an image do not meet the true needs of the radiologist.
Other efforts at marking a radiological image have been set forth in the patent literature and are summarized below.
U.S. Pat. No. 4,813,062 (Gilpatrick '062)
The Gilpatrick '062 patent describes a crayon-like marker composed of substances that are detectable by X-ray examination. Specifically, Gilpatrick discloses a crayon or marking pencil containing a radiopaque substance uniformly dispersed within a waxy medium (e.g., paraffin wax) that is used as a tool for applying a mark to an object for inspection.
The Gilpatrick '062 method for applying a radiopaque marker does not, however, disclose the use of such a device to indicate areas of interest on a medical patient. The stated use of the Gilpatrick device and method is to place a radiopaque mark on a substrate. Specifically, the radiopaque marker is intended for use in the context of textile inspection. Accordingly, Gilpatrick fails to disclose a method for using a radiopaque marker tool in a medical imaging process.
Because the Gilpatrick device is intended for use in textile examination, possible detrimental effects of human contact with certain radiopaque compositions may not have been considered by Gilpatrick. This lack of consideration is evidenced by the fact that the marker disclosed in the '062 patent focuses on compositions containing heavy metals (e.g., bismuth, lead), which in some forms can be toxic to humans.
U.S. Pat. No. 2,462,018 (Wood '018)
The Wood '018 patent also discloses a marker containing a material that is detectable by X-ray examination. Specifically, Wood discloses a crayon or pencil containing fine particles of radiopaque metal atoms in a carrier or vehicle material, such as a wax. Wood alternatively discloses the use of a brush or pen for applying a radiopaque substance in a liquid carrier. The marking device may then be used to apply an X-ray observable mark on the object to be inspected.
Like the Gilpatrick '062 patent, however, the Wood '018 patent discloses a number of heavy metals (e.g., lead, bismuth, uranium, thallium) as the appropriate radiopaque substances. In fact, Wood specifically focuses on lead and limits the list of appropriate materials to elements having an atomic weight of at least 184, which is even greater than the acceptable range noted by Gilpatrick. Thus, Wood likewise fails to disclose a radiopaque marker that is designed to be safe for use on medical patients.
Unlike Gilpatrick, however, the Wood '018 marker is disclosed for use in anatomical X-ray work. The disclosure of the use of the X-ray marker in a medical context is very limited, and appears that the use of the Wood X-ray marker is intended more for marking the plate or film for identification purposes than to mark the patient to pinpoint the site of injury.
U.S. Pat. No. 4,506,676 (Duska '676)
The Duska '676 patent describes a radiopaque identifier for identifying the location of concern on a medical patient so that the examining physician can communicate to an X-ray technician or diagnosing radiologist the area on a radiograph to be analyzed. Specifically, Duska discloses a tape provided with a series of radiopaque markings forming a dashed line along the center of the tape. The radiopaque material disclosed is barium sulfate, but Duska also notes that other pigments or powdered or finely divided material known to be opaque to X-radiation may also be appropriate. Accordingly, Duska discloses the use of safe radiopaque substances applied to a medical patient to identify the location of interest in medical imaging.
Duska does not, however, disclose any tool that applies the radiopaque substance directly to a patient's skin. The patent's disclosure is limited to a tape having radiopaque markings, so the examining physician is limited in the types of marks that can be made by the shape of the tape. Thus, although Duska discloses a radiopaque marking device and system that allows an examining physician to communicate the area of interest to later parties examining the resulting X-ray, the '676 patent fails to provide a better way to mark the skin in a visible manner so that the image is taken of the correct spot and the resulting picture is marked for diagnosing that spot.
U.S. Pat. No. 5,193,106 (DeSena '106)
The DeSena '106 patent describes a device for marking landmarks on the skin as a means of identifying areas of interest under x-radiography. The device involves a radiopaque material affixed to an adhesive tape. The radiopaque material may be formed into a variety of shapes, such as a circle, triangle, or square to provide a marker that encircles the point of interest. The markers are pre-cut and affixed to a roll of tape and distributed from a dispenser, so the markers can be easily dispensed.
DeSena does not disclose a pencil, pen, marker, or any other tool that applies the radiopaque substance, though. Further, the DeSena markers are limited in size and shape to the preformed stickers. In fact, DeSena notes that the markers disclosed are different from prior markers in that they are specifically designed to identify small areas. Accordingly, the examining physician is limited in the markings that can be made and may be especially limited if a relatively large area is the area to be analyzed. Thus, although DeSena discloses another form of radiopaque marker, the '106 patent likewise fails to disclose each and every element of the current invention
This review of the pertinent art shows that none of the published material or known products on the market fully address the radiologists' problems of image placement during the patient scanning process or image marking to focus the radiologists' review. The invention herein is, therefore, an important advancement over all prior work in the related fields.